A conventional power supply device having a function of detecting the presence or absence of a foreign object, as shown in FIG. 5, is known (for example, refer to patent reference 1). In the power supply device disclosed by this patent reference 1, a plurality of sensor coils 102 in each of which its winding axis is orthogonal to a transmission antenna 101 are disposed (only one sensor coil is shown in FIG. 5) so as to detect a foreign object existing in surroundings 103 of the sensor coils 102. A reception antenna (not shown) is configured in the same way.